US 11908500

I'll research US11908500 and any associated litigation.

Let me search for CAFC 2026 dockets involving this patent.

Let me check specifically for Federal Circuit (CAFC) dockets and any assertion of the '500 patent.

US 11,908,500 B2 — Research Summary

Scope note: I searched for the specific number 11908500. Results returned only this patent (and its own family members); I did not auto-expand to similar numbers (e.g., 11,908,592 or 11,908,500-adjacent IDs). Where I could not verify something against an authoritative source, I flag it explicitly.

1. Bibliographic data

Prosecution-chain note (matters for term and family): This is a continuation of application 15/985,661 (which issued as US 11,133,031), which in turn descends from 15/925,749 (US 11,138,997) and 11/424,859 (US 9,978,413) — all claiming the 2006-06-17 priority date. It has a child continuation, 18/503,873 (US 2024/0079030 A1, reported abandoned).

2. Abstract (as printed)

"A multilayer exchange spring recording media consists of a magnetically hard magnetic storage layer strongly exchange coupled to a softer nucleation host. The strong exchange coupling can be through a coupling layer or direct. The hard magnetic storage layer has a strong perpendicular anisotropy. The nucleation host consists of one or more ferromagnetic coupled layers. For a multilayer nucleation host the anisotropy increases from layer to layer. The anisotropy in the softest layer of the nucleation host can be two times smaller than that of the hard magnetic storage layer. The lateral exchange between the grains is small. The nucleation host decreases the coercive field significantly while keeping the energy barrier of the hard layer almost unchanged. The coercive field of the total structure depends on one over number of layers in the nucleation host. The invention proposes a recording media that overcomes the writeability problem of perpendicular recording media."

3. Plain-language overview of the claims

Claim 1 (the sole independent claim) — a magnetic recording system. It recites two cooperating pieces:

1. A writing head (i.e., a magnetic write transducer, not just the medium).
2. A disk bearing a magnetic recording medium that comprises:
   • an essentially non-magnetic substrate;
   • a granular hard magnetic storage layer with perpendicular anisotropy, having a coercive field H_s (measured without any other magnetic layer) and a thickness between 3 nm and 30 nm;
   • a granular hard magnetic nucleation host with perpendicular anisotropy, disposed on the hard storage layer in a columnar manner (its grains line up with those of the storage layer), having a coercive field H_n (without the hard layer), where the numeric relationship 0.7 T < H_n < H_s holds — i.e., the host is "hard" in absolute terms (>0.7 T) but softer than the storage layer;
   • the nucleation host having a magnetic polarization J_s = μ₀M_s between 0.3 T and 1.0 T;
   • the host and the storage layer separated by a coupling layer 0.1–3 nm thick, that coupling layer sitting directly between them; and
   • the coupling between host and storage layer being ferromagnetic (not antiferromagnetic).

In short: a disk whose write-assist ("nucleation host") layer is itself a hard perpendicular-anisotropy granular layer, strongly ferromagnetically bridged to an even harder granular storage layer through a very thin (≤3 nm) coupling layer, paired with a write head.

Dependent claims 2–11 (narrowing limitations):

• Claim 2: the coupling layer provides an exchange constant A > 10⁻¹⁴ J/m.
• Claim 3: hysteresis-loop squareness S of the medium is within 10% of that of the hard storage layer alone (i.e., adding the host doesn't spoil the loop shape).
• Claim 4: the nucleation host contains at least one of Fe and O.
• Claim 5: nucleation-host grains have average diameter >2 nm and <10 nm.
• Claim 6: nucleation host thicker than 7 nm.
• Claim 7: hard storage layer based on an FePt alloy.
• Claim 8: that FePt alloy is an L1₀-phase alloy.
• Claim 9: hard storage layer is an alloy from the group CoPt, CoPtCr, CoPtCrB, CoPtCrTa, CoCr.
• Claim 10: nucleation host has more than one layer with differing anisotropy.
• Claim 11: anisotropy assumes more than one value in a substantial magnetic portion of the nucleation host (the "graded"/G-layer species of the disclosure).

Practical read: the independent claim is a hard/hard exchange-spring architecture. Notably, the independent claim does not require the anisotropy to increase layer-to-layer toward the storage layer (that teaching is in the specification, and only appears in dependent claim 10's "different anisotropy"); the independent claim instead fixes the boundaries with numeric limitations (H_n > 0.7 T, J_s 0.3–1.0 T, storage 3–30 nm, coupling layer 0.1–3 nm, ferromagnetic coupling).

4. Litigation and CAFC status — important caveat

I found no evidence that US 11,908,500 itself has been asserted or is on a 2026 CAFC docket. Searches for the number in litigation contexts returned nothing tying this specific patent to a suit or appeal. What I did find is substantial activity on sibling patents in the same family/specification, which is relevant context but must not be conflated with the '500:

• MR Technologies GmbH v. Western Digital Technologies, Inc., No. 8:22-cv-01599 (C.D. Cal., filed Aug. 2022) — asserted US 9,928,864 and US 11,138,997. Jury verdict 2024-07-26: infringed and not invalid; $262,388,800 damages, plus prejudgment interest reported at ~$117.3M. Western Digital's FY SEC disclosure reports a $130M global settlement in April 2025 resolving this and a second MRT action.
• MR Technologies GmbH v. Western Digital, No. 8:24-cv-01848 (C.D. Cal., filed Aug. 22, 2024) — asserted the '734 patent (US 12,020,734); dismissed per joint motion (order dated July 8, 2025; motion dated May 16, 2025).
• MR Technologies GMBH v. Toshiba America Electronic Components, Inc. et al., No. 8:25-cv-00786 (C.D. Cal., filed Apr. 15, 2025) — asserted the '864, '997 and '734 patents.
• Resonac Hard Disk Corp. et al. v. MR Technologies GmbH, No. 3:25-cv-08631 (N.D. Cal., filed Oct. 9, 2025) — Resonac declaratory-judgment action (non-infringement).
• PTAB: IPR2026-00014, -00015, -00016 (Resonac v. MR Technologies) challenging the '864, '997 and '734 patents; as of the filings I retrieved (Jan. 2026), institution decisions were pending on discretionary-denial briefing under the March 26, 2025 Director memo.
• MR Technologies v. Seagate (D. Minn., No. 0:25-cv-01460) — Seagate motion to dismiss partly denied; contributory-infringement claims dismissed as abandoned.

Uncertainty flags (stated plainly):

1. I could not confirm any Federal Circuit appeal docketed in 2026 involving US 11,908,500, nor any 2026 CAFC appeal in the MRT family generally. My search tooling reached district-court dockets, PTAB filings and news; a definitive CAFC check would require a direct search of the Federal Circuit's PACER/CM-ECF docket (and the appeal from the WD judgment appears to have been mooted by the April 2025 settlement).
2. Dates, assignee data, "Active" status and the 2026-06-17 anticipated-expiration entry come from Google Patents' bibliographic rendering (fetched 2026-09-24 per the source header) — these are stated by Google Patents as assumptions rather than legal conclusions, and I have not independently verified them against USPTO Patent Center.
3. The priority date of 2006-06-17 is the earliest filing in the chain (US 11/424,859); the '500 application itself was filed 2021-09-27. Anyone relying on the term should confirm the continuation/priority chain against the official file wrapper.

5. One-line bottom line

US 11,908,500 B2 (Suess / MR Technologies GmbH) claims a hard-perpendicular write head + disk system in which a granular, hard (H_n > 0.7 T) nucleation host with J_s of 0.3–1.0 T is ferromagnetically exchange-coupled through a 0.1–3 nm coupling layer to a 3–30 nm granular hard storage layer; it is a continuation in the widely litigated Suess exchange-spring family, but I found no indication that this particular member has been asserted or is before the Federal Circuit in 2026.

I'll search for litigation involving US patent 11908500.

I'll first check whether any AIA trial proceedings exist for this patent or its family, since the structured block defaults to none.

Significant family-level activity surfaced. Let me now check specifically whether any proceeding targets the '500 patent itself, and map the family IPRs.

US 11,908,500 — AIA Trial Proceeding Review

Bottom line up front: The structured ODP feed reports zero AIA trial proceedings against US 11,908,500. My independent web checks are consistent with that: the only PTAB activity in this patent family targets three sibling patents (the '864, '997, and '734 patents), not the '500 patent. No proceeding number is invented below — the three real proceedings I list are expressly flagged as family-level, not '500-level.

Proceedings overview

Total AIA trial proceedings on US 11,908,500: 0 — 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution-denied. Consequently, all eleven claims (1–11) of the '500 patent are UNTESTED at the PTAB, and there is no § 315(e)(2) estoppel running against any party on any claim. For a defendant, the operative defensive posture is not "the patent is hardened by surviving IPRs" (it never faced one) and not "the claims are canceled" (none are) — it is "uncontested and unchallenged before the Board, with an unusually short runway left on the term and a family-wide track record of institution denial for would-be challengers."

Proceedings on US 11,908,500

(None on file) — no petitioner has challenged this patent at the PTAB

• Type: N/A — no Inter Partes Review, Post-Grant Review, or Covered Business Method review is on file.
• Filed: N/A (no proceeding).
• Status: No AIA trial activity per the USPTO Open Data Portal structured block; no contrary proceeding surfaced in web searches keyed to "11,908,500," "11908500," and the patent owner/petitioner pairings below.
• Judge panel: N/A.
• Petition grounds: N/A — no claims, art, or statutory basis have been put at issue for this patent.
• Institution decision: N/A.
• Final Written Decision: N/A. No claim of the '500 patent has ever been adjudicated by the Board.
• Settlement / termination: N/A.
• Appeal: N/A as to PTAB. (The related district-court judgment discussed below is not a PTAB appeal.)
• Defensive value: Neither side has Board-side estoppel. You are free to raise any § 102/§ 103 ground against claims 1–11, subject only to the § 315(b) one-year clock if and when the '500 patent is served on you, and to General Plastic-type discretionary risk if you file serially. Because the patent is untested, there is also no FWD to cite and no cancelation to leverage — the burden of proof sits with you, not with a prior petitioner's record.

Why the absence is notable here. In this family, the opposite is true of the siblings: US 9,928,864, US 11,138,997, and US 12,020,734 were all hit with IPRs in October 2025. The '500 patent (granted 2024-02-20, filed 2021-09-27 as a continuation) was not challenged, and it also does not appear in the asserted-patent sets I reviewed from the Western Digital, Toshiba, or Seagate complaints — which recited the '864, '997, '734, '413, and '031 patents. An unasserted, near-expiry continuation is a rational thing for challengers to skip.

Adjacent PTAB activity in the same family (does not involve US 11,908,500)

These are real proceedings and are included only for strategic context — none of them names the '500 patent or its claims.

IPR2026-00014 — Resonac Hard Disk Corporation et al. v. MR Technologies GmbH

• Type: Inter Partes Review
• Patent challenged: US 9,928,864 (family parent)
• Filed: 2025-10-08
• Status: Discretionary Denial (i.e., institution refused). Record shows a Director Discretionary Decision: Deny dated 2026-02-03; petitioner then filed a Request for Refund of Post-Institution Fees on 2026-03-02, with a notice: refund approved on 2026-03-09 — consistent with a non-instituted case winding down.
• Judge panel: Not disclosed in the public materials reviewed.
• Petition grounds: Not independently itemized for this docket in the sources reviewed.
• Institution decision: Denied 2026-02-03 on discretionary grounds. Patent Owner's preliminary response argued the petition should be denied under § 314(a) and the Director's March 26, 2025 Interim Processes for PTAB Workload Management memorandum, emphasizing that (i) a jury had already found the '864/'997 claims valid and infringed on 2024-07-26 ($262,388,800 verdict), (ii) Resonac knew of the patents by 2022 yet waited until October 2025 — after seeing Western Digital's challenges fail — and (iii) the challenge was duplicative of the settled expectations created by the litigation. Counsel: Petitioner — Dion M. Bregman (Morgan Lewis); Patent Owner — James A. Milkey (Russ August & Kabat).
• Final Written Decision: None issued.
• Settlement / termination: Not a settlement — terminated via the denial/refund path.
• Appeal: None identified (a denial is not appealable to the Federal Circuit as of right).
• Defensive value: A roadmap showing the Board's receptivity to § 314(a)/Director-memo denials in this exact family. If you file against the '500 patent after a long period of knowledge, expect the same arguments.

IPR2026-00015 — Resonac Hard Disk Corporation et al. v. MR Technologies GmbH

• Type: Inter Partes Review
• Patent challenged: US 11,138,997 (family child)
• Filed: 2025-10-08
• Status: Discretionary Denial (institution refused). I did not independently confirm the decision date for this docket; the parallel docket's denial issued 2026-02-03.
• Judge panel: Not disclosed in the public materials reviewed.
• Petition grounds (from Petitioner's own stipulation letter of 2026-01-08):
  • Ground 1 — Takeniori, § 103, claims 1–2, 5–7
  • Ground 2 — Takeniori in view of Li, § 103, claims 4, 9
• Institution decision: Not instituted (discretionary). Notably, the petition record contains a Sotera-style stipulation submitted by Resonac on 2026-01-08 (agreeing, upon institution, not to pursue in the N.D. Cal. DJ case any § 102/§ 103 patent-or-print-publication ground raised or reasonably raisable in the IPR) — but Patent Owner's preliminary response still argued Resonac "fail[ed] to offer any stipulation" and had structured the petitions to preserve "multiple bites at the apple" via the district cases and its 2025-10-09 declaratory judgment action. The stipulation and the POPR share a filing date, so treat the timing dispute as contested on the record.
• Final Written Decision: None issued.
• Settlement / termination: No settlement; the stipulation expressly reserved the right to raise all invalidity grounds in district court if institution was denied — which is what happened.
• Appeal: None identified.
• Defensive value: The Takeniori / Li art packs are reusable prior-art starting points for an ECC-media challenge — but they were not tested on the merits, so they carry no estoppel and no preclusive weight.

IPR2026-00016 — Resonac Hard Disk Corporation et al. v. MR Technologies GmbH

• Type: Inter Partes Review
• Patent challenged: US 12,020,734 (family child; itself the continuation that followed the '500 patent's line)
• Filed: 2025-10-08
• Status: Discretionary Denial (institution refused); decision date not independently confirmed in the sources reviewed.
• Judge panel: Not disclosed in the public materials reviewed.
• Petition grounds: Not independently itemized in the sources reviewed; the supporting declaration was from Prof. Jian-Gang Zhu (Carnegie Mellon University, Data Storage Systems Center), addressing the unpatentability of the challenged claims of the '997/'734 family in view of prior art including Suess 2004, Suess 2005, and Dobin.
• Institution decision: Not instituted (discretionary); Petitioner's Updated Mandatory Notices filed 2026-01-08 added the co-pending N.D. Cal. DJ action, Resonac Hard Disk Corp. et al. v. MR Technologies GmbH, No. 3:25-cv-08631 (N.D. Cal.).
• Final Written Decision: None issued.
• Settlement / termination: No settlement.
• Appeal: None identified.
• Defensive value: Same as above — useful art, no merits ruling, no estoppel.

Related district-court context (non-PTAB, for completeness): MRT asserted the '864 and '997 patents against Western Digital; on 2024-07-26 a C.D. Cal. jury found them infringed and not invalid and awarded $262,388,800. Western Digital publicly stated it would appeal; I did not confirm a Federal Circuit docket number in the sources reviewed, so I do not state one here. The '734 case against WD settled and was dismissed 2025-05-16. MRT asserted the '864, '997, and '734 patents against Toshiba (C.D. Cal., filed 2025-04-15) and Seagate (D. Minn., filed 2025-04-15).

Strategic summary

Claim status on the '500 patent. All eleven claims are UNTESTED: zero CANCELED, zero SUSTAINED, zero adjudicated. Claims 1–11 stand exactly as issued on 2024-02-20. Any assertion letter citing claim 1 is not vulnerable to a "that claim is already dead" rebuttal — the IPR-estoppel/knockout playbook that works against frequently-challenged patents simply has no purchase here. The corollary is equally important: MRT has no Board-side win to wave around either; there is no FWD finding its claims patentable and no Board-sanctioned claim construction for it to borrow.

Estoppel landscape. No IPR against the '500 patent was ever instituted, and no FWD issued in any proceeding in this family. Under § 315(e)(2), estoppel attaches only after an IPR is instituted and an FWD issues — so no petitioner (Resonac, Western Digital, or anyone else) is estopped from anything. Resonac's conditional Sotera stipulation was expressly keyed to institution and is therefore inoperative; Resonac reserved, and retains, its § 102/§ 103 district-court grounds. For a newly-sued defendant on the '500 patent, the entire prior-art universe is available, subject to: (i) § 315(b) — you must petition within one year of service of a complaint alleging infringement of this patent (if the '500 has not been served on you, that clock has not started, which is a meaningful advantage); (ii) § 315(a)(1) — do not first file a DJ action of invalidity; and (iii) General Plastic/§ 314(a) discretionary risk if your petition is a "follow-on" to a failed one. Note that MRT/Toshiba/Seagate's April 2025 suits did not assert the '500 patent, and WD's 2022 suits did not either — so § 315(b) appears not to have been triggered against anyone on this patent.

Pattern signals. (1) One repeat petitioner, three petitions, all denied: Resonac filed a coordinated three-petition campaign on 2025-10-08 against the '864/'997/'734 family and was shut out at institution — none reached a merits FWD. The Board's willingness to deny here (jury-verdict-plus-delay narrative, March 2025 workload memo) is a documented headwind for any new challenger in this family. (2) No defensive aggregator: there is no Unified Patents or similar entity in the chain — all family challenges trace to a commercial indemnitor (Resonac) protecting a customer relationship. (3) The patent owner has never had to defend a Board appeal on this patent, and there is no IPR-based Federal Circuit precedent from this family. (4) Timing pressure cuts against a new IPR on the '500: Google Patents lists an anticipated expiration of 2026-06-17 for the '500 patent (20 years from the 2006-06-17 earliest filing), which — if the term figure is correct — means the patent has already lapsed as of today (2026-09-29). Treat this as a high-priority verification item, not a settled fact: confirm Patent Term Adjustment under § 154(b) and any terminal disclaimer on the face of the '500 patent and in USPTO Patent Center, since continuations in this chain show divergent expiry dates (e.g., the '864 parent is listed as running to 2029-08-22 on PTA, while the 15/985,661 continuation is listed at 2026-09-05). If the term figure holds, damages are confined to the window from issuance (2024-02-20) to 2026-06-17, there are no ongoing royalties to negotiate, and a broadening reissue is no longer available (the two-year post-grant window closed 2026-02-20). Also note the PGR window on this patent closed on 2024-11-20 (nine months post-grant), and CBM review is unavailable, so IPR is the only live AIA vehicle — which makes the § 315(b) calculus decisive if the patent is asserted.

Recommended next steps

1. Verify the term before anything else. Pull the face of US 11,908,500 and the USPTO Patent Center "Patent Term Adjustment" record for application 17/486,608. Google Patents lists anticipated expiration at 2026-06-17; if confirmed, the patent expired before today's date, which moots most of a damages case and dramatically reduces the value of an IPR. If instead there is unclaimed PTA, recompute the runway.
2. If the '500 patent has now been served on you, calendar the § 315(b) date immediately and file within one year of service. Because no proceeding exists, you have a clean slate: no § 315(e)(2) estoppel, no adverse FWD claim constructions, no General Plastic "second bite" problem (you would be the first petitioner).
3. Harvest the Resonac filings as free prior-art scaffolding. The three petitions (IPR2026-00014, IPR2026-00015, IPR2026-00016) and their exhibit sets — including Prof. Jian-Gang Zhu's declaration, Suess 2004, Suess 2005, and Dobin — are public via PTAB E2E and mirror the '500 patent's specification and claim architecture. The '997 Ground 1 (Takeniori, § 103) and Ground 2 (Takeniori + Li, § 103) formulations are directly transplantable starting points. But litigate them on the merits — they were never adjudicated, so they carry zero weight on their own.
4. The dispositions you can quote today are the two denials you can cite by docket — and only to argue discretionary posture, not merits: PTAB E2E for IPR2026-00014 (U.S. Patent 9,928,864, institution denied 2026-02-03) and IPR2026-00016 (U.S. Patent 12,020,734). There is no FWD anywhere in this family to quote; the only merits win is the 2024-07-26 district-court jury verdict on the '864/'997 patents, which does not bind a third party on the '500 patent but is the practical backdrop to any negotiation.
5. Check the Federal Circuit docket for Western Digital's appeal of the 2024-07-26 judgment and for the N.D. Cal. DJ action's progress (Resonac Hard Disk Corp. et al. v. MR Technologies GmbH, No. 3:25-cv-08631), where MRT's motion to dismiss/transfer was heard on 2026-02-12. A Federal Circuit reversal on the '864/'997 claims would materially change the value of the entire family, including the untested '500 patent. I did not locate a CAFC docket number in the sources reviewed, so I do not supply one.

Sources for the specific materials cited above: PTAB E2E petition filings (ptacts.uspto.gov), the IPR2026-00014 case record at ipverse.greyb.com, and the district-court record docketed at PacerMonitor. The patent text itself is from Google Patents US11908500B2.

Caveat on scope: the conclusions above rest on the ODP structured block plus the searches I ran. Two items I could not fully verify and therefore flag rather than assert: (a) the exact institution-decision dates for IPR2026-00015 and IPR2026-00016, and (b) whether any proceeding against the '500 patent was filed very recently and is not yet indexed. If you need certainty, re-run the ODP API and search PTAB E2E for "11,908,500" directly before relying on this.

I'll research the assignment chain and cross-reference with litigation/entity data.

Ownership-chain analysis — US 11,908,500 B2

Scope note: The authoritative patent text supplied for this matter (Google Patents rendering of US 11,908,500 B2, fetched 2026-09-24) contains exactly one post-filing assignment legal event for this patent. My supplementary searches reached Google Patents legal events, the Austrian company register, SEC filings, PTAB papers, and district-court coverage, but I was not able to retrieve the Assignment Center's correspondent/attorney-of-record field for the recorded assignment. That is flagged in place below rather than guessed.

Inventors

Unusual ownership patterns to note:

• No employer/university assignment was ever recorded. The inventorship chain begins and ends with the individual — the Google Patents legal events for this patent record "Application filed by Individual" (2021-09-27) and "Priority to US17/486,608" with no institutional assignee anywhere in the record. For a university-employed physicist, a 16-year period (2006 → 2022) of personal ownership is the single most unusual feature of this chain and is a potential title-risk item (inventor-vs-employer rights under Austrian university IP practice). I could not verify the contractual position, so I state it as an observation, not a conclusion.
• The "all inventors gone within 12 months" precursor-to-fire-sale pattern is inapplicable — there is one inventor, and he is also the buyer's principal. The inverse pattern applies: the inventor retained title for 16 years and then moved it to a company he controls.
• MRT's own litigation narrative (its complaints, echoed in the D. Minn. and C.D. Cal. filings) states Suess "used his own micromagnetics modeling software… to perform advanced micromagnetic simulations" in the May 2006 timeframe — i.e., the inventive work is characterized as independent of an employer's facilities, consistent with the absence of any institutional assignment.

Original assignee

• Named on the issued patent: Individual — Dieter Suess (original assignee field: "Individual"). There was no corporate original assignee, no product, and no operating business at the time of the 2006 filing.
• Shipped a product embodying the claims? No. The original assignee is a natural person who did not manufacture magnetic recording media. The technology was, however, adopted by third parties — MRT's complaints allege "almost all state-of-the-art HDDs now rely on this invention," and Western Digital's FY2024 10-K discloses a $384M accrual and a $130M April 2025 global settlement.
• Primary line of business / current status: Not a business entity. Suess remains an academic (University of Vienna); the commercial vehicle he later formed, MR Technologie GmbH, FN 537289g, Nibelungengasse 11/4, 1010 Wien, Austria, was entered in the Austrian register on 2020-08-29 with stated purpose "Entwicklung, Erwerb und Verwertung von Technologien für magnetische Aufzeichnungssysteme" (development, acquisition and exploitation of technologies for magnetic recording systems) and capital of EUR 35,000 (sources: https://www.evi.gv.at/f/537289g, https://www.firmenabc.at/mr-technologie-gmbh_zfXI).
• Name discrepancy to flag (do not auto-correct): the US record renders the assignee as "MR TECHNOLOGIES, GMBH, AUSTRIA", while the Austrian register renders the company as "MR Technologie GmbH" (and some trade press describes it as German — that appears to be error; the seat is Vienna). Whether these are the identical legal person is highly likely given the common principal, but I have not verified the entity-number-to-US-record mapping, so I record both spellings literally.

Assignment timeline

The Assignment Center-rendered record for this patent contains one post-filing conveyance:

• 2022-06-13 (executed / stated effective) / recorded 2025-05-02 — Reel 071010/0971
  • Conveyance: Assignment ("ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)")
  • Assignor: SUESS, DIETER
  • Assignee: MR TECHNOLOGIES, GMBH, AUSTRIA (Austrian register name: MR Technologie GmbH)
  • Correspondent: Not retrievable from the sources I could reach. The Google Patents legal-event rendering of Reel 071010/0971 does not carry the correspondent/attorney field, and my queries against Assignment-Center-indexed pages returned nothing. This field must be pulled directly from Assignment Center for the reel above; I decline to name a correspondent without a source. (Related but different counsel of record in the litigation context, for completeness and not as the assignment correspondent: Russ August & Kabat — MRT "certified litigation counsel, Russ August & Kabat, as the only nonparty having a pecuniary interest in the outcome of its litigation," per Mondaq's Oct. 2024 write-up.)
  • Context: Transfer to the inventor's own monetization vehicle, executed ~2.5 months before MRT's first infringement complaint (filed 2022-08-26), but recorded only on 2025-05-02 — i.e., roughly 35 months after execution and ~2 weeks after the April 2025 WD global settlement. Because the '500 was still a pending application in June 2022 (filed 2021-09-27, published 2022-01-13, granted 2024-02-20), this reads as a confirmatory/catch-up recordation of a continuation member rather than a fresh transfer. I cannot determine from available sources whether sister family members were recorded separately in 2022.

No other records. I found no security agreement, license, merger, change-of-name, or release recorded against this patent, and no earlier inventor-to-entity assignment. If Assignment Center shows additional entries under a different patent-number spelling or under application 17/486,608, this section should be supplemented.

Timeline diagram

timeline
    title Ownership of US 11908500
    2006 : Filed by Dieter Suess as individual
    2020 : Suess forms MR Technologie GmbH
    2021 : Continuation filed in same family
    2022 : Assigned to MR Technologies GmbH
         : WD suit filed by MR Technologies
    2024 : Patent issued
         : WD jury verdict 262M
    2025 : Assignment recorded at USPTO
         : WD global settlement 130M

NPE / troll-pattern signals

1. Shell-entity transfer — partially present.
   Evidence for: Reel 071010/0971 moves the patent from a natural person to MR Technologie GmbH, an entity whose registered purpose is technology acquisition and exploitation, capitalised at EUR 35,000, with no manufacturing operation — and Suess testified he "formed MR Technologies in 2020 to license his patents." Evidence against the "shell" framing: the assignee is a registered Austrian GmbH (FN 537289g, Wien, entered 2020-08-29) with a real seat, not a single-purpose Delaware/Texas LLC fronted by a registered-agent address, and its controller is the inventor himself rather than an anonymous third party.

2. Known asserter in the chain — not present (as to the enumerated lists).
   Neither Dieter Suess nor MR Technologies / MR Technologie GmbH appears in the enumerated public NPE directories (Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Erich Spangenberg entities). I could not independently confirm any Unified Patents / RPX "high-frequency plaintiff" designation for MRT; note only that MR Technologies is tracked as a patent owner in Unified Patents' database (e.g., its page for family member US 11,133,031).

3. Repeat correspondent across the chain — unclear / cannot be established.
   With a single recorded assignment on this patent, recurrence is not even testable within this chain, and the correspondent field itself was not retrievable. This signal should be re-run after pulling Reels for family members US 9,978,413 / 9,928,864 / 11,133,031 / 11,138,997 / 12,020,734; if the same recording attorney appears across those, that would be the finding.

4. Cascading transfers — not present. One conveyance in 16+ years; no chained LLCs, no shared-address assignees, no <24-month sequence.

5. Pre-litigation transfer — present as to the campaign, not present as to this patent.
   The assignment is executed 2022-06-13, about ten weeks before MRT's first HDD complaint (2022-08-26, MR Techs. GmbH v. Western Digital Techs., Inc., No. 8:22-cv-01599, C.D. Cal.). The literal definition ("within 6 months before the first infringement suit naming this patent") is not met, because US 11,908,500 has not (per my searches) been named in any complaint. That suit asserted the '413, '864, '031 and '997 patents. The '500 has likewise not been named in the 2024 '734 action, the April 2025 Toshiba action (which asserts '864, '997, '734), the Resonac DJ action (three patents), or the Resonac IPR2026-00014/15/16 petitions. Flag for follow-up: the recording date (2025-05-02) post-dates all of these filings, which is consistent with the '500 being held in reserve as the family term runs out on 2026-06-17.

6. Bankruptcy fire-sale — not present. No bankruptcy, receivership or judicial-sale records in this chain.

7. Privateering — not present. There is no operating-company transferor; the transferor is the individual inventor, so the classic "operating company hands patents to an NPE to sue competitors" posture does not apply. (Litigation posture worth noting separately, without labelling it privateering: Resonac's IPR petitions allege MRT "pursued a litigation strategy aimed at suing downstream customers while avoiding the upstream supplier," i.e., customer-suiting rather than supplier-suiting.)

8. Defensive aggregator — not present. The chain terminates at MR Technologies GmbH; no RPX / AST / LOT / Unified / OIN acquisition is recorded.

Adjacent portfolio-management observation (not one of the eight signals): the family shows serial continuation filing in the final years of a fixed 2006-06-17 priority (applications filed 2018, 2021 [twice] and 2023, the last one reported abandoned). Because all members share the 2006 priority, continuations do not extend term — but they do produce fresh, differently-worded claim sets (e.g., the '734 patent's claim 1, drafted around a first/second ferromagnetic layer with K2>K1) that can be timed to later products. The '500's own claim 1 is the numeric-boundary variant (H_n > 0.7 T, J_s 0.3–1.0 T, 0.1–3 nm coupling layer, ferromagnetic coupling).

Verdict

NPE — moderate confidence.

Justification: Reel 071010/0971 (executed 2022-06-13, recorded 2025-05-02) transfers the patent from the individual inventor to MR Technologie GmbH, an Austrian entity whose registered purpose is the acquisition and exploitation of magnetic-recording technology, which manufactures nothing and which exists to license and litigate this family — and that transfer was executed roughly ten weeks before the family's first infringement complaint (C.D. Cal., 2022-08-26). That is one strong signal (licensing-only transferee) plus supporting context (serial continuation filings in the end-of-term years; a family-wide assertion campaign against HDD makers that produced a $262.4M verdict and a $130M settlement per WD's 10-K), but it does not reach "high confidence" because there is no anonymized shell LLC, no third-party aggregator or known NPE-list principal, no cascade of transfers, the assignee is controlled by the named inventor rather than an outside acquirer, and US 11,908,500 itself has not been asserted or petitioned against as far as I can determine. If the goal is a high-confidence call, the next step is to pull the family's other reel/frame records for the correspondent and cascade analysis.

Verification links:

• USPTO Assignment Center (search by patent number): https://assignmentcenter.uspto.gov/
• Google Patents legal events (source of Reel 071010/0971 and its 2022-06-13 effective date): https://patents.google.com/patent/US11908500/en#legalEvents
• Austrian company register, MR Technologie GmbH FN 537289g: https://www.evi.gv.at/f/537289g
• Western Digital FY2025 10-K legal proceedings ($130M April 2025 global settlement): https://www.sec.gov/Archives/edgar/data/[106040](/patent/106040)/000010604025000038/R26.htm

Explicit uncertainty flags: (i) the assignment correspondent is unknown to me and must be read off Assignment Center; (ii) whether "MR TECHNOLOGIES, GMBH" in the US record is legally identical to "MR Technologie GmbH" (FN 537289g) is unverified beyond the shared principal and Vienna seat; (iii) the "no other assignments" finding is based on the single patent's rendering plus my searches — it does not rule out separately recorded instruments on sister family members, and it does not rule out unrecorded (hence ineffective against later purchasers) transfers.

I'll verify the key cited references before building the prior-art analysis. Let me run several targeted searches in parallel.

Prior-Art Analysis — US 11,908,500 B2

Cross-reference housekeeping (per operating rules, I flag rather than silently fix):

• Date inconsistency: this task states "Current Date: April 26, 2026." The system context and the patent fetch header both say 2026-09-29 / 2026-09-24. I use the source dates as authoritative and treat "April 2026" as the analysis-staging date. No substantive impact.
• Builds on prior sections: I do not repeat the bibliographic table, abstract, or claim breakdown already generated. One point from those sections is now more important and is expanded here: the '500 is a continuation claiming 2006-06-17 priority, which drives the pre-AIA § 102 analysis below.

1. Two corrections / clarifications to the "cited art" list

Flag 1 — The Google Patents "Patent Citations (65)" list is not all prior art. It mixes (a) true prior art on the face of the patent with (b) the applicant's own family members. The following entries in the 65-item list are the same invention (Suess/MR Technologies family) and are therefore not prior art against the '500:

US 9,928,864 B2; US 9,978,413 B2; US 11,133,031 B2; US 11,138,997 B2; US 2007/0292720 A1; US 2018/0211689 A1; US 2018/0268852 A1; US 2024/0079030 A1; and the JP/KR/US "Family Applications" entries. Any § 102 assertion built on these would be an improper "same-inventor/same-family" citation. The US20070292720A1 entry, in particular, is the pre-grant publication of the instant family's original 2006 filing.

Flag 2 — Several candidate references post-date the priority date. Because the '500 claims 2006-06-17 (assumed), references filed after 2006-06-17 are not prior art at all unless they carry an earlier effective date. On the cited list this removes, as prior art, at least: US 7,572,526 B2 (filed 2007-02-18), US 8,557,409 B2 (filed 2010-08-02), and US 9,966,095 B2 (filed 2016-08-02). Their earlier-filed siblings (e.g., Berger '210, Fullerton '545) remain available.

2. Legal framework applied (and why "anticipation" is a high bar here)

• Statute: Because the effective filing date is 2006-06-17 (pre-AIA), pre-AIA 35 U.S.C. § 102 governs. § 102(a)/(b) art needs a date before 2006-06-17 (or 2005-06-17 for § 102(b) printed publications); § 102(e) art needs a U.S. filing date before 2006-06-17.
• Anticipation discipline: A reference anticipates only if it discloses every element of the claim as arranged. Because every dependent claim 2–11 incorporates all limitations of claim 1, no dependent claim can be anticipated unless claim 1 is first anticipated by that same reference. This single point drives most of the analysis below.
• Claim 1's hard-to-find elements: (i) a writing head coupled to (ii) a granular, "hard" nucleation host whose coercive field satisfies 0.7 T < H_n < H_s (i.e., > 0.7 T — the host is hard in absolute terms, not a soft layer); (iii) host J_s between 0.3 T and 1.0 T; (iv) a coupling layer 0.1–3 nm directly between host and storage layer; (v) ferromagnetic coupling; (vi) storage layer 3–30 nm, granular, perpendicular anisotropy, columnar with the host.
• Key consequence: The overwhelming majority of the cited art is hard/soft exchange-spring (ECC) media — a hard layer exchange-coupled to a low-anisotropy soft layer. Claim 1 as issued is a hard/hard architecture. That mismatch is precisely why the art of record is § 103 material, not § 102 material. The most influential references were, in fact, used by the Office under § 103, as the family's file histories and the 2026 PTAB petitions show (see § 5).

Bottom-line § 102 answer up front: On the record of the '500, I find no single cited reference that clearly and unambiguously discloses every element of claim 1 as arranged, and therefore no clean § 102 anticipation of claim 1 or, derivatively, of claims 2–11. The art below is instead the art most relevant for § 103 invalidity. The closest calls are Fullerton '545/'418 and Berger '210 (detailed below).

3. Tier 1 — The most relevant references (closest art)

These are the references that actually disclose a hard/perpendicular, granular, exchange-coupled multilayer with an interposed coupling layer — i.e., the elements overlapping claim 1.

4. Tier 2 — Substantively relevant (mostly § 103; claim-specific)

5. The art that actually mattered in prosecution/PTAB (important context)

The most probative "prior art" indicators for this family are the references the examiner and petitioners actually relied on. Those are not the ancient/background citations; they are:

• Li (US 7,846,564 / US 2007/0072011) — Seagate gradient-H_k, granular, columnar, tailored exchange coupling.
• Fullerton et al. (US 2007/0243418 / US 7,488,545) — laminated RLs of ferromagnetically exchange-coupled ferromagnetic layers with a thin CL.
• Fullerton2 (US 2003/0108721) — cited for the L1₀ FePt/CoPt high-anisotropy materials.
• Berger et al. (US 7,550,210) — hard/hard exchange-spring with similar anisotropy fields.
• Girt (antiferromagnetically coupled perpendicular recording media) and Takenoiri (two-layer exchange-coupled stack with coupling layer) — cited in the PTAB petitions against sibling patents.

These are visible in the file-history/PTAB excerpts retrieved (e.g., the Office's rejections over Fullerton et al., and the "Li / Victoria / Fullerton / Girt / Takenoiri" invalidity narrative in the MR Tech v. Western Digital record). Caveat: those rejections and petitions target the sibling patents US 9,928,864 / 11,138,997 / 12,020,734, not the '500. I did not find a § 102 rejection of the '500 itself on any cited reference.

6. Full citation table — all patent documents cited on the '500

Dates are as printed (filing date / publication or issue date). "Tier" = relevance to the '500's claims.

7. Non-patent literature cited (for completeness, brief)

The '500 lists 46 NPL items. For § 102/§ 103 purposes the operative ones are: Hagedorn, "Analysis of Exchange-Coupled Magnetic Thin Films," J. Appl. Phys. 41, 2491–2502 (1970) (layer-stacking → switching-field reduction); Loxley et al., "Theory of Domain Wall Nucleation in a Two Section Magnetic Wire," IEEE Trans. Magn. 37(4), 2098–2100 (2001) (two-section wall-nucleation factor ≈4); Abraham & Aharoni, Phys. Rev. 120(5), 1576–1579 (linear anisotropy variation); Victora & Shen, "Composite Media for Perpendicular Magnetic Recording," IEEE Trans. Magn. 41(2), 537–542 (2005) and Wang et al., APL 86, 142504 (2005) (hard/soft composite; the "Victora" art relied on in the family's litigation). Note that several NPL entries (Suess et al. 2005 APL; Suess et al. JMMM 290-291; Suess "Multilayer Exchange Spring Media…" 2006) are the inventor's own work and function as background/§ 103 "closest prior art," not § 102 anticipatory disclosures.

8. Bottom line

1. No clean § 102 anticipation of claim 1 — and therefore of any of claims 2–11 — by the art cited on the face of US 11,908,500. The cited references are predominantly hard/soft exchange-spring media, AFC media, or unrelated art (two are wholly unrelated: Seiko Epson micro-lenses; Etech semiconductor spin device), whereas the issued claim 1 is a hard/hard architecture with explicit numeric boundaries (0.7 T < H_n < H_s, J_s 0.3–1.0 T, 0.1–3 nm coupling layer, 3–30 nm storage layer, ferromagnetic coupling).
2. The most dangerous references are Fullerton US 7,488,545 / US 2007/0243418 (A), Berger US 7,550,210 (B), Li US 7,846,564 / US 2007/0072011 (C), and Nolan US 7,384,699 (D). They are best characterized as § 103 art — which matches how the Office and the 2026 PTAB petitioners actually used them against the sibling patents.
3. Which claims are most exposed: claim 11 (graded/continuous anisotropy) and claim 10 (multi-layer host of differing anisotropy) are most directly taught by Li '564/'011 (and Do '834); claims 7–9 (FePt/CoPt/CoPtCr materials) are taught by Fullerton '418/'545 + Fullerton2 '721; claims 2 and 1's coupling-layer limitation are taught by Fullerton '545 and Nolan '699.
4. Do not assert the family's own documents (US 2007/0292720, US 9,928,864, US 9,978,413, US 11,133,031, US 11,138,997, US 2018/0211689, US 2018/0268852, US 2024/0079030) as prior art — they are the same invention/inventor family.
5. Priority-date caution: references filed after 2006-06-17 (e.g., US 7,572,526, US 8,557,409, US 9,966,095) are not prior art if the '500's claims retain the 2006-06-17 effective date. That date is Google Patents' assumption; verify the continuation/priority chain against the USPTO file wrapper before relying on it.

Confidence/limitations: The reference descriptions and dates above are drawn from the patent's own citation list plus web retrieval of the cited documents; I verified the substance of the Tier-1 items (Fullerton '545/'418, Berger '210, Li '564, Nolan '699). I did not locate any § 102 rejection of the '500 itself, nor any Federal Circuit docket involving the '500; a definitive prior-art-date and claim-by-claim anticipation opinion would require the full USPTO file wrapper (all Office Actions/applicant responses) and the pending PTAB petition papers, which I could access only in part.

I'll ground this analysis in the prior-art citations listed on the patent page, and do a quick check for any validity challenges specific to the '500.

Obviousness Analysis — US 11,908,500 B2 under 35 U.S.C. § 103

(Builds on the patent summary and litigation summary already generated. All references are the ones listed in the "Citations (55)", "Patent Citations (65)" and "Non-Patent Citations (46)" sections of the source page for US 11,908,500. Where I map a reference's disclosure to a claim element, I flag whether I am working from the reference's title/abstract on the page or from text I retrieved for that reference.)

1. Threshold determinations that drive the whole analysis

(a) Which § 103 governs. The '500 application (17/486,608) was filed 2021-09-27, i.e., after the AIA's 2013-03-16 cutoff, but it is a continuation of 15/985,661 → 15/925,749 → 11/424,859, all claiming 2006-06-17. If every issued claim is entitled to the 2006-06-17 effective filing date, pre-AIA § 102/103(a) applies and prior art must predate the applicant's invention (practically, 2006-06-17). If any claim's effective filing date is on/after 2013-03-16, AIA § 102/103 applies, prior art is measured from 2021-09-27, and essentially the entire prior-art corpus (including the 34 "Families Citing this family" documents from 2006–2021) becomes available — which would make invalidity almost certain. I analyze below on the applicant-favorable assumption (2006-06-17 priority), and flag the priority risk in § 9.

(b) Art-discipline point. The 34 entries in "Families Citing this family" (e.g., US 7,582,368, 2006-09-14; KR 20080105386, 2007-05-30; US 2009/0237835, 2008-03-20; US 7,964,013, 2009; US 8,163,405, 2009; US 9,142,240, 2010; US 8,940,418, 2010; US 9,028,985, 2011; Seagate's 2016 US 9,990,951; Fuji's 2016 MY185710A) are all later filings and are therefore not prior art against a 2006-06-17 date. Only the citations list matters for a § 103 attack on these claims.

(c) The self-disclosure problem. Several NPL items are the inventor's own work. Under pre-AIA § 102(b) the inventor's own printed publication is still prior art if it published more than one year before 2006-06-17 — i.e., before 2005-06-17. That sweeps in Suess et al., "Exchange spring recording media for areal densities up to 10 Tbit/in²," JMMM 290-291 (2005), available online 18 Dec 2004 (expressly "incorporated herein by reference" in the '500's own Background), which discloses the hard/soft/hard tri-layer with a domain-wall-assisted reversal mechanism. The later Suess items (APL July 2005, Intermag Apr 2005, MMM Nov 2005, APL submitted 03 Jun 2006) fall inside the grace window and are "by others"-problematic under § 102(a); they are best used as evidence of the state of the art and of motivation, not as § 102 art. Hagedorn (1970), Loxley (2001), Kneller & Hawig (1991), Victora & Shen (Feb 2005), Wang et al. (2005), Inaba et al. (Oct 2005), Shen et al. (JAP 97, 2005), Supper et al. (Oct 2005), Dobin & Richter (arXiv 15 May 2006) are all clean pre-2006-06-17 art by others.

(d) The gap between H_k and H_c. The claim recites coercive fields (H_s, H_n), while the key references speak mostly in anisotropy fields (H_k). That is the single most contestable link in the chain and I identify it explicitly in § 3.

2. Claim 1, element by element

Claim 1 therefore reads on a single reference, US 7,552,210, for everything but the system-level "writing head" and the precise 0.7 T floor.

3. Combination 1 (primary): Berger '210 / Fullerton '418 + a head-and-disk system reference

References combined: US 7,552,210 B2 and/or US 2007/0243418 A1 (HGST; both filed before 2006-06-17, both § 102(e)/(a) art) + US 6,881,497 or US 5,583,727 (system/head).

Why the combination is motivated:

• '210's stated objective is verbatim the '500's: "The medium shows improved writability, i.e., a low switching field, as well as lower intrinsic media noise, over a medium with a conventional single-layer RL," while "because both ferromagnetic layers in this exchange-spring type RL have a high anisotropy field, the thermal stability of the medium is not compromised."
• The references and the '500 address the identical problem (the superparamagnetic limit vs. write-field limit) and are in the identical field (perpendicular granular magnetic recording media), so the KSR "same field of endeavor / same problem" rationales apply directly.
• Selecting a thin (0.2–1.5 nm) RuCo or Pt/Pd coupling layer to mediate ferromagnetic exchange is a known technique applied to a known structure to achieve a predictable result (KSR, 550 U.S. 398, 417 (2007)); '210 itself frames CL thickness as a routine result-effective variable for tuning coupling strength.
• Adding a write head to a perpendicular recording medium is the sine qua non of the product ('500 Background; '210 Fig. 1 head-field discussion).

The contestable element — "0.7 T < H_n": An examiner or challenger must bridge H_k → H_c. The bridge is available from the '500's own specification, which defines "hard" as H_c > 0.5 T, and from the record of the MR Technologies v. Toshiba pleading (on the same family), which characterizes commercial PMR media as having H_s ≈ 2.0 T and a nucleation host with H_n < 1.8 T. That is powerful admission-style evidence that hard (≫0.7 T) nucleation hosts were the industry norm by the relevant time. But absent a reference expressly reporting H_c > 0.7 T for the softer layer, the 0.7 T floor is the claim's best defense — and, under In re Aller / In re Peterson / Titanium Metals v. Banner, a numerically bounded selection from a disclosed, result-effective range is prima facie obvious if the range is disclosed or close to disclosed.

4. Combination 2: Seagate anisotropy/coercivity-gradient media + HGST exchange-spring structure

References combined: US 7,846,564 B2 / US 2007/0072011 A1 / US 2011/0076516 A1 (Seagate; all priority 2005-09-27) — "Perpendicular magnetic recording media with magnetic anisotropy/coercivity gradient and local exchange coupling" — in view of US 7,425,377 B2, US 7,684,157 B2, US 7,989,096 B2 (HGST; all 2005-02-04) — "Perpendicular recording media having an exchange-spring structure" — and US 7,833,640 B2 ("Intermediate tri-layer structure for perpendicular recording media," 2005-08-19).

Mapping: the Seagate references supply the spatially varying anisotropy / coercivity architecture in a perpendicular granular recording layer with local exchange coupling — precisely the functional core of the '500's "nucleation host" (its disclosure's G-layer and multi-layer species). The HGST exchange-spring and tri-layer references supply multi-layer hard perpendicular stacks with exchange coupling across thin interlayers, plus the known mechanism (the lower-anisotropy layer reverses first and drags the higher-anisotropy layer).

Motivation: all three bodies of art are directed to the same trilemma, and the Seagate reference expressly ties the anisotropy gradient to the write-field depth profile — the same physical argument used in '210 and, later, in the '500 ('"the write head produces a larger magnetic field and larger field gradient near the surface of the RL"'). A POSA optimizing the gradient would arrive at a host whose softest layer is still "hard," because the whole point is preserving thermal stability of each grain.

5. Combination 3: domain-wall-assisted recording literature + composite-media literature

References combined: Dobin & Richter, "Domain Wall Assisted Magnetic Recording" (arXiv, 15 May 2006) and Suess et al., Exchange spring media for perpendicular recording, APL 87 (2005) — both pre-2006-06-17 and by others (Dobin/Richter) — in view of Victora & Shen, Composite Media for Perpendicular Magnetic Recording, IEEE TM 41(2), Feb 2005, pp. 537-542; Wang et al., APL 86 (2005) 142504; and Hagedorn, JAP 41 (1970) 2491-2502 ("Analysis of Exchange-Coupled Magnetic Thin Films," showing a factor-of-five H_c reduction when a finite anisotropy in the soft layer was assumed).

Mapping: domain-wall-assisted reversal of a bilayer with a pinned wall at the hard/soft interface (the '500's stated mechanism); the coupling-layer thickness range and its optimization (Inaba et al.; Shen et al., FeSiO soft layer / [Co/PdSi]N hard layer); and — critically for the "hard host" limitation — Hagedorn's finite-anisotropy result and its discussion in the '500's own Background.

Motivation: the '500's Background concedes that the field knew all of these pieces, and that the reduction was already attributed to domain-wall pinning at the hard/soft interface. Under KSR, an "obvious to try" rationale applies where there is a finite number of identified, predictable solutions — here, the anisotropy value of the softer layer, which the art treats as a continuum between perfectly soft (K=0) and equal-to-hard.

6. Dependent claims 2–11

7. Motivations to combine, stated in KSR terms

1. Same field / same problem. Every reference is a perpendicular granular magnetic recording medium aimed at the writeability–thermal-stability trade-off. The '500's Background concedes this explicitly.
2. Predictable result from known elements. Layer count, per-layer anisotropy, coupling-layer material and thickness were all known levers with known effects (Hagedorn; Victora & Shen; Inaba; '210).
3. Explicit teaching of the claimed benefit by the art. US 7,552,210's abstract states the claimed advantage — writeability improved without compromising thermal stability because both layers are high-anisotropy. This directly undercuts the '500's asserted point of departure ("In previous works it was not shown that a finite value of the anisotropy in the soft magnetic layer does not reduce the thermal stability").

   ⚠ Contradiction flag: the '500's Background characterization of the prior art is in tension with the express disclosure of US 7,552,210 (filed 2006-03-09). If '210 is enabled for the high-H_k/high-H_k ferromagnetic-CL structure, the '500's stated premise for patentability is factually incorrect as of the relevant date. This is the highest-value issue in the case.

4. Design incentives. The write-field depth profile (larger field near the surface) gave a POSA a concrete reason to place the higher-anisotropy layer nearer the head and a still-hard layer below — exactly the '500 geometry.
5. Optimization of result-effective variables (In re Aller, In re Peterson, Titanium Metals): H_n/H_s ratio, coupling-layer thickness (0.1–3 nm), J_s (0.3–1.0 T), storage thickness (3–30 nm) and host thickness (>7 nm) are all disclosed or squarely bracketed by the art.

8. Counterarguments a patent owner will press

• Teaching away. Victora & Shen (2005), Wang et al. (2005) and Inaba et al. (2005) taught that the soft layer should be genuinely soft and that a decoupling layer was needed to reduce exchange coupling. If the art taught that coupling must be weakened, that cuts against '210's ferromagnetic-CL architecture. Counter: '210 and US 7,384,699 teach the opposite (tunable, weak-to-strong ferromagnetic coupling) at 0.2–1.5 nm, and '210's claims expressly cover "first and second ferromagnetic layers have substantially different anisotropy fields."
• Unexpected results. The '500 asserts that coercivity can be decoupled from thermal stability and reduced by up to 10× (Figs. 2, 5) while ΔE is unchanged (Fig. 6). But that core result is also reported for the earlier bilayers/tri-layers in the Background, and Hagedorn had already shown a ~5× H_c reduction with finite soft-layer anisotropy.
• Objective indicia — the strongest real-world card. In MR Technologies v. Western Digital (C.D. Cal. 8:22-cv-01599), the jury found the asserted claims not invalid, and MRT's expert (Dr. Mark Re, whose declaration is Exhibit 2011 in IPR2026-00014) opined that the asserted claims are non-obvious over "Li alone or with Victora or Berger," "Berger alone or with Hagedorn or Li," and "Victora alone with Hagedorn or Li," and invoked substantial objective indicia (industry adoption — "almost all state-of-the-art hard disks rely on this idea"; ~800 citations; copying). Note that "Berger" in that litigation is, by strong inference, the same Andreas Klaus Berger named first on US 7,552,210 — i.e., the primary reference I identify here was, apparently, already run against the sibling claims and rejected by a jury. (Inference from the name match and the reference list; not independently confirmed — verify against the trial record.) The '500's claim 1, however, is materially narrower than the '864/'997 claims that were tried (it adds the mandatory ferromagnetic coupling layer of 0.1–3 nm, the H_n > 0.7 T floor, and the 0.3–1.0 T J_s window), so the jury verdict is not dispositive for the '500.

9. Overall assessment and caveats

• Strongest § 103 case: US 7,552,210 B2 (and/or US 2007/0243418 A1) as the primary reference, alone or in view of US 6,881,497/5,583,727 for the system element, and in view of Hagedorn (1970) and Victora & Shen (2005) for motivation. Claim 1's structural limitations — granular perpendicular hard storage layer, granular hard host disposed on it, thin ferromagnetic coupling layer — are all taught. The residual gap is the numeric 0.7 T coercivity floor on the host and the H_k→H_c conversion.
• Mechanical invalidity route: if the '500's claim 1 is held not entitled to the 2006-06-17 priority date (a real risk: the "0.7 T < H_n < H_s," "J_s 0.3–1.0 T" and "coupling layer 0.1–3 nm" limitations are the kind of narrowing matter added to late continuations), then AIA § 102(a)(1) makes available everything published before 2021-09-27 — including the entire 34-document forward-citation set and the '500's own family's publications — and invalidity becomes very likely to establish.
• I have not verified (i) the full text of US 7,552,210/US 2007/0243418 beyond the passages retrieved; (ii) any express H_c (as opposed to H_k) value for the softer layer in any cited reference; (iii) the '500's file history (the 2022-07-05 non-final action and any amendments/arguments that produced the numeric limitations); (iv) whether "Berger" in the WD litigation is US 7,552,210. Each of those should be checked against the reference PDFs, PAIR/Patent Center, and the PTAB trial record (IPR2026-00014 exhibits 2010–2021) before any of the above is relied upon.